D’Alembert’s Principle
Unit 8: Mechanical Principles of Engineering
,Learning Aims
By the end of this session, you will be able to understan
Momentum
Conservation of momentum
Conservation of energy
D’Alembert’s principle
2
Unit 8: Mechanical Principles of Engineering
,Momentum
The ‘quantity of motion’ possessed is referred
to momentum.
It is a product of the mass m and velocity v.
The units of mass are ….
The units of velocity are ….
The units of momentum are or
Momentum is found experimentally that the
average force required to bring to rest a small,
quickly moving mass may be as great as that 3
to bring to rest a large, slowly moving mass.
, Momentum
A change of momentum may be produced
in a body:
By a change in mass, as in a rocket
ejecting burnt fuel.
By a change in the direction of velocity,
as in a body rotating in a circular path.
By a change in the magnitude of the
velocity, as in an accelerated body.
By a change in both mass and velocity.
4
Unit 8: Mechanical Principles of Engineering
,Learning Aims
By the end of this session, you will be able to understan
Momentum
Conservation of momentum
Conservation of energy
D’Alembert’s principle
2
Unit 8: Mechanical Principles of Engineering
,Momentum
The ‘quantity of motion’ possessed is referred
to momentum.
It is a product of the mass m and velocity v.
The units of mass are ….
The units of velocity are ….
The units of momentum are or
Momentum is found experimentally that the
average force required to bring to rest a small,
quickly moving mass may be as great as that 3
to bring to rest a large, slowly moving mass.
, Momentum
A change of momentum may be produced
in a body:
By a change in mass, as in a rocket
ejecting burnt fuel.
By a change in the direction of velocity,
as in a body rotating in a circular path.
By a change in the magnitude of the
velocity, as in an accelerated body.
By a change in both mass and velocity.
4
